Photographic color couplers

ABSTRACT

This invention relates to compounds useful as photographic couplers having the general formula: WHEREIN X is alkyl, Y is either carbonyl or sulfonyl, R is alkyl having from five to 20 carbon atoms and Z is hydrogen or halogen. The invention also relates to the use of the abovementioned compounds in photographic emulsions.

United States Patent Guzziet al.

1151 3,692,833 1451 Sept. 19, 1972 [54] PHOTOGRAPHIC COLOR COUPLERS [72] Inventors: Alberto Guzzi, Viale Della Liberta; Remo Magagnoli, Via Gramsci, both I of Ferrania, Italy [22] Filed: Aug. 27, 1970 [21] Appl. No.: 67,569

Related us. Application Date [62] Division of Ser. No. 701,995, Jan. 31, 1968,

Pat. No. 3,591,384.

[30] Foreign Application Priority Data Primary Examiner-Henry R. Jiles Assistant Examiner-Harry 1. Meat: Attorney-Carpenter, Kinney & Coulter [57] ABSTRACT This invention relates to compounds useful as photographic couplers having the general formula:

wherein X is alkyl, Y is either carbonyl or sulfonyl R is alkyl having from five to 20 carbon atoms and Z is hydrogen or halogen. The invention also relates to the use of the abovementioned compounds in photographic emulsions.

5 Claims, 2 Drawing Figures PHOTOGRAPHIC COLOR COUPLERS This application is a division of application Ser. No. 70l,995,now US. Pat. No. 3,591,384. r

This invention relates to a class of couplers capable of forming stable cyan or blue-green dyes by color development in color photographic materials.

In the production of colored images by the color development of silver halide emulsion layers in a multilayer film construction the image formed after light exposure of the reducible silver salts is developed in the presence of a coupler, i.e. a compound which reacts with the oxidation products of the color developer to form a dye. Cyan images are generally obtained by the formation of an indophenol dye from a l-hydroxy- Znaphthamide coupler.

One important requirement of color couplers used in color photography is the ability to resist bleeding or migration through and outside of the photographic emulsion layers in which they are contained. An effective means for solving the migration problem is provided by the dispersed coupler method, in which the coupler is dissolved in high boiling organic solvents, such as tricresyl phosphate or dibutyl phthalate, and the resulting solution is intimately dispersed throughout the silver halide emulsion. To obtain the best results in terms of the dispersion and photographic efficiency the solution of coupler in the organic solvent should be highly concentrated. Couplers which are highly soluble in or miscible with the organic solvent are therefore commonly selected for use in dispersed coupler systems. In general, couplers having a relatively low melting point are quite soluble in such organic solvents. However, it is also desirable to select couplers which produce dyes having good stability to light, heat on on.

O o ONIIQ O o ONHQ l O 11H2a H CH:

O c ONH- S OzCioHss OH cm 0 ONH Cl 5 oz iu sa Table I shows some analytical data of these illustrative couplers, the analyses being made after only one crystallization of the raw reaction product. Included are their desirable melting points. Their high degree of solubility in organic solvents normally used for dispersing couplers in a gelatin emulsion permits the use of a solvent/coupler ratio far lower than 1.0 without a!!! ot eab qqw nx eldg d a...

TABLE I -OH 0, percent H, percent N, percent 01, percent percent Melting point content Crystalliza- Coupler No. F.) Found Cale. Found Cale. Found Cale. Found Cale. found tlon solvent 21515-2192 1 (102404. 0}) 78.46 78.30 8.28 8.11 3.00 3.04 99.27 Ethanol. 2 1&2??? 72.55 72.9 7.25 7.3 7.16 7.17 93.81 Heptane. 8 99.41 Acetic acid.

O O NH- wherein X is alkyl, preferably a lower alkyl (C C Y is either carbonyl or sulfonyl, R is C -C alkyl, and Z is hydrogen or halogen, preferably chlorine or bromine. These couplers are easily obtainedin a very high purity by methods described later.

Illustrative couplers are as follows:

formed by normal color development procedures. For example, coupler I can be incorporated into a photographic emulsion with 1 part dibutyl phthalate containing 4 parts of coupler.

In addition to the abovementioned characteristics the claimed couplers react with N,N-dialkyl-p-phenylenediamine during color development to provide dyes which are particularly stable to light, heat and moisture. For example, if one of these couplers is dissolved in dibutyl phthalate, dispersed in a photographic emulsion, coated onto a transparent support, exposed and developed with diethyl-p-phenylenediamine, the resultant color shows no noticeable change in either color density or hue after exposure to a xenon lamp for 10 hours. Coated samples prepared in similar manner were exposed through a scale of decreasing densities, i.e. grey scale, and developed in color developer with excellent sensitometric results, even after storage for 24 hours at a temperature of 194.0F. (90C.) and a relative humidity of percent. In FIG. 1 curve A is the sensitometric curve (read in red light) for coupler (l) and curve B is the sensitometric curve for coupler 1) .after 24. hours storage under the abovementioned conditions. These curves show'the excellent stability of dyes prepared from the couplers of this invention.

The spectral absorption of the cyan dyes obtained these couplers and N,N-dialky1-p-phenof theaspectrum, which is very desirable. in FIGNZ an illustrative :comparison of 'the spectral absorption of N,N-diethyl piphenylenediamine developed couplers indibutyl-phthalate, absorption curve A being that of abovementioned coupler (3) and absorption curve B being that of a coupler of the formula:

OOH

The coupler of curve B is a known coupler having some structural similarity to the couplers-of this invention. From a comparison of curves A and B it is apparent .thatcurve A represents .lower absorption in the :500 and 600 millimicronregion than curve B.

The couplers of the present invention can be prepared by reacting the suitable amines with l-hyroxy-2-naphthoic acid or l-hydroxy-4-halo-2-naphthoic acidderivatives, such as their phenyl esters. In particular, the preparations of some couplers of said class were carried .out in the following way:

.a. .Preparation of 4-methyllaurophenone Into a 500 ml. flask containing a suspension of 59 g. of AlCl in 168 ml. of dry toluene, 69.2 g. of lauroyl chloride were rather quickly introduced. The temperature rose to 140.0F. (60C.). The mixture was kept under stirring at a temperature of 176.0F. (80C.) for 22 ;hours, then was poured with vigorous stirring into 1,000 ml. of water and 66.5 ml. of concentrated hydrochloric acid. After about one hour the organic layer was removed and washed, first witha 1% Na cO solution and then with water. The toluene solution was then dried with calcium chloride, and the solvent was removed under vacuum. The residue, consisting of a readily solidifying oil, was crystallized from ethanol. Yield: 58.8 g. (67 percent). M.p.: 113.0-l15.5F. (4S46.5C.) Analysis: for C I-1 calculated: C% 83.57; H% 10.94 found: C% 83.27; 11% 10.94.

b. Preparation of 3-nitro-4-methy1laurophenone In a beaker provided with stirrer and thermometer, was placed 190 ml. of HNO (D1.52) and then 69.9 g. of 4-methyllaurophenone was added in increments. The operation was carried out as rapidly as possible while maintaining the reaction temperature below 44.-6F. (7C.). After completion of the ketone addition the mixture was stirred for an additional minutes and then the mixture was added dropwise into l'liter of ice water. The precipitated product was filtered off and thoroughly washed with water, then allowed to dry in the air. By crystallization from methanol 86.4 g. (70 percent) of the nitro derivative with M.p.: 122.0-1 23.8F. (50-5 1C.) was obtained.

c. Preparation of 3-amino-4-methyllaurophenone 56.4 ,g. of 3-nitro-4 methyllaurophenone was dissolved in --a boiling mixture of 530 ml. of -percent acetic acid and 260 ml. of ethanol. Then 106 g. of' iron powder was slowly added. After completion of the addition boiling was-continued for about 30 minutes,- after which the ferrous slime was hot flltered and the filtrate was poured with stirringinto 17.5 ml. of water. The

amine which separated was filtered offand thoroughly washed with water. Yield of raw product: 48.6: g. By crystallizing the raw'product from 485 ml. of ethanol and decolorizing with'charcoal, 41.5 .g. (81.2 percent) of product having a M.p.of -167.0-l70.6F. (75-77 C.) was obtained. Analysis: for c gH NO calculated: N% 4.84; found:-N% 4.65; -NH content: 100.00-percent.

d. Preparation of 1 hydroxy -2-(2'-methyl-5'-lauroyl)naphthanilide (Coupler 1 In a Claisen flask arranged for distillation under vacuum a mixture of 63.6 g. of 3-amino-4-methyllaurophenone and 63.6 g. of phenyl l-hydroxy-2- naphthoate was melted. At this point vacuum was applied in order to remove the phenol which was liberated as the reactioncontinued. After about half an hour the amount of distilled phenol was 22 g. (theory: 22.6 g.). The residue was crystallized from ethanol. Yield of coupler: 91.5 g.

e. Preparation of l-hydroxy-4-chloro-2-(2'-methyl-5'- lauroyl)-naphthanilide (Coupler 2) By working in the same way as described for the coupler 1 and employing an equivalent amount of phenyl 1-'hydroxy-4-chloro-2-naphthoate instead of phenyl 1- hydroxy-Z-naphthoate 86 g. of coupler was obtained after crystallization from heptane.

f. Preparation of p-tolyl cetyl sulfone Into a reaction flask 75 g. of sodium p-toluenesulfinate tetrahydrate, 300 ml. of ethanol and 91.5 g. of cetyl bromide were introduced. The mixture was heated at reflux on a water bath for 24 hours and was then diluted with 1 liter of water. A white precipitate was obtained which, after being filtered, washed and dried, was purified by crystallization from ethanol. Yield: 82.1 g. M.p.: 154.4-156.2"F. (68-69C.) Analysis: for C I-[ 0 s calculated: C% 72.57; H% 10.5; S% 8.4; found: C% 72.36;H% 10.4; S% 8.28.

g. Preparation of 3-nitro-4-methylphenyl cetyl sulfone It was obtained in a way similar to the 3-nitro-4- methyllaurophenone by using 112 ml. of fuming HNO; for 56.8 g. of p-tolyl cetyl sulfone. Yield: 55.2 g. (from ethanol) M.p.: 161.6-163.4F. (72-73C.).

h. Preparation of 3-amino-4-methylphenyl cetyl sulfone Prepared in a way similar to the 3-amino-4-methyllaurophenone, it was crystallized from ethanol. M.p.: 140.0-41.8F. (60-61C.) Analysis: Nl-l,% content 98.27.

i. Preparation of l-hydroxy-2-(2'-methyl-5-cetylsulfonyl)-naphthanilide (Coupler 3) By following the same procedure as the Coupler l 47.3 g. of 3-amino-4-methylphenyl cetyl sulfone was reacted with 34.7 g. of phenyl l-hydroxy-2-naphthoate. 59.2 g. of Coupler (3) was obtained.

j. Preparation of l-hydroxy-4-chloro-2-(2'-methyl-5'- cetylsulfonyl)-naphthanilide (Coupler 4) The product was obtained by procedures similar to those used in the preceding examples from 39.5 g. of 3- amino-4-methylphenyl cetyl sulfone and 32.8 g. of phenyl l-hydroxy-4-chloro-2-naphthoate. Yield was 43 grams. k. Preparation of l-hydroxy-2-(2-methyl-5-decylsulfonyl) naphthanilide Obtained by a synthesis similar to that of the Coupler (3), using decyl bromide instead of cetyl bromide.

The properties of the intermediates are the followmg:

TABLE ll lntermediate M.p. ("F.) Crystallization Solvent p-tolyldecylsulfone l25.6l29.2 ethanol (SP-54C) B-nitrO-Z-methylll4.8-l l8.4 ligroin phenyldecylsulfone (46-48C.) 3-amino-4-methyl- 68.0 phenyldecylsulfone 20C.)

The coupler was obtained by the reaction of the raw amine with phenyl l-hydroxy-Z-naphthoate and, after crystallization from from ethanol, the M.p. was 273.2277.5F. (l34-136.5C.). Analysis: --Ol-l% content=96.87.

EXAMPLE 1 2 grams of Coupler (l) was dissolved in a mixture consisting of 0.5 ml. of dibutyl phthalate and 12 ml. of ethyl acetate by heating on a boiling water bath. The resulting clear solution was poured into 40 ml. of 4 percent gelatin containing 4 ml. of percent sodium tetradecyl sulfate solution. At a temperature of about l04.0F. (40C.) the mixture was dispersed in a homogenizer. The dispersion thus obtained was added to 200 g. of silver halide photographic emulsion sensitized to red light. The thus modified emulsion was spread on a transparent support, dried and exposed through an original. By chromogenic development in a N,N-diethyl-p-phenylenediamine developer, a negative blue-green colored image was obtained. The stable blue-green dye forming the image had an absorption peak at 688 mp.

EXAMPLE 2 A dispersion of the following formulation:

Coupler (3) 2 grams dibutyl phthalate 4 ml. ethyl acetate l2 ml. 4% gelatin 40 ml. 10 I: sodium tetradecyl sulfate solution 4 ml.

hydroxylamine hydrochloride l gram diethyl-p-phenylenediamine sulfate 2.8 grams sodium tripolyphosphate 2 grams anhydrous sodium carbonate 65 grams anhydrous sodium sulfite 25 grams potassium bromide l.2 grams water to make I000 ml. I

(pH l0.8-8.l l with NaOH) After the usual steps of bleaching, fixing and washing, a blue-green colored negative image of the original was obtained. The absorption curve of the blue-green dye forming the image is the same as curve A in FIG. 2. The absorption peak of the dye lies at 697 702 mp.

Various other embodiments of the present invention will be apparent to those skilled in the art without departing from the scope thereof.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

l. A photographic coupler of the formula OH x 30 ONH z inn wherein X is alkyl of one through six carbon atoms, Y is either carbonyl or sulfonyl, R is alkyl having from five to 20 carbon atoms and Z is hydrogen or halogen.

2. 1-Hydroxy-2-( 2 '-methyl-5 '-lauroyl)-naphthanilide.

3. l-Hydroxy-4-chloro-2-( 2-methyl-5 '-lauroyl)- naphthanilide.

4. l-Hydroxy-2-( 2 '-methyl-5 '-cetylsulfonyl)- naphthanilide.

5. l-Hydroxy-4-chloro-2-( 2 -methyl-5 '-cetyl-sulfonyl )-naphthanilide.

*nni'inn SKATES enema @ER'ETFEQATE @E QQRREQTKQN Patent No. 3,692,833 Dated September 19, 1972 lnventofls) Alberto Guzzi and Remo Magagnoli It is certified that error'appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 1, line 36, Table I, 0,; percent" should be -C, percent-.

Signed and sealed this 29th day of May 1973.

(SEAL) Attes-t:

EDWARD M.FLETCHE'R,JR. ROBERT GOTTSCHALK Attesting Officer Commissioner of Patents F ORM PO-1050 (10-69) USCOMM-DC 60376-P69 A u.s. GOVERNMENT PRINTING OFFICE: 1959 0-366-334 

2. 1-Hydroxy-2-(2''-methyl-5''-lauroyl)-naphthanilide.
 3. 1-Hydroxy-4-chloro-2-(2''-methyl-5''-lauroyl)-naphthanilide.
 4. 1-Hydroxy-2-(2''-methyl-5''-cetylsulfonyl)-naphthanilide.
 5. 1-Hydroxy-4-chloro-2-(2''-methyl-5''-cetyl-sulfonyl)-naphthanilide. 